JP2016537900A - Techniques for downlink coordinated multipoint (CoMP) communication using unlicensed radio frequency spectrum bands - Google Patents

Abstract

Techniques for downlink coordinated multipoint (CoMP) procedures for access to contention-based radio frequency spectrum bands are described. The base station performs a contention procedure, such as a clear channel assessment (CCA) procedure, to access the radio frequency spectrum band. The base station determines whether it has won the contention for the time period and communicates whether it has won the contention to the other base stations in the CoMP cooperating set. Based on information exchanged between base stations in the CoMP cooperating set, cooperative communication with two or more of the other base stations in the CoMP cooperating set is initiated for the UE.

Description

Cross reference
[0001] This patent application is filed September 30, 2014, "Techniques for Downlink Coordinated Multi-Point (CoMP) Communications Using Unlicensed Radio Frequency Spectrum Band", each assigned to the assignee of the present application. U.S. Patent Application No. 14 / 501,929 by Luo et al. And entitled "Techniques For Downlink Coordinated Multi-Point (CoMP) Communications Using Unlicensed Radio Frequency Spectrum Band" filed November 25, 2013 Claims priority to US Provisional Patent Application No. 61 / 908,534 by Luo et al.

  [0002] The present disclosure relates to wireless communication, for example, and more particularly to techniques for coordinated multi-point (CoMP) communication in unlicensed radio frequency spectrum bands.

  [0003] Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and so on. These wireless networks may be multiple access networks that can support multiple users by sharing available network resources.

  [0004] A wireless communication network may include a number of access points. A cellular network access point may include several base stations, such as a Node B (NB) or an evolved Node B (eNB). Wireless local area network (WLAN) access points may include a number of WLAN access points, such as Wi-Fi nodes. Each access point may support communication for several user equipments (UEs) and often may communicate with multiple UEs simultaneously. Similarly, each UE may communicate with several access points and sometimes with multiple access points and / or access points that employ different access technologies. The access point may communicate with the UE via the downlink and uplink. The downlink (or forward link) refers to the communication link from the access point to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the access point.

  [0005] In some deployments, wireless communication may employ coordinated multipoint (CoMP) downlink transmission, in which two or more base stations may transmit data to the UE. Such CoMP transmission includes dynamic point selection (DPS) in which different base stations transmit data to the UE at different times and joint transmission in which two or more base stations simultaneously transmit data to the UE ( One or more of several CoMP schemes including JT (joint transmission) may be used.

  [0006] As cellular networks become more frequently used, operators are seeking ways to increase capacity. One approach may include the use of a WLAN to offload some of the cellular network traffic and / or signaling. Unlike cellular networks that operate in the licensed radio frequency spectrum band, Wi-Fi networks generally operate in the unlicensed radio frequency spectrum band and therefore follow established rules to provide fair access to the spectrum. WLANs (such as Wi-Fi networks) can provide attractive features because various entities are available for use. However, access to the unlicensed radio frequency spectrum band allows coexistence by base stations using the same or different techniques for accessing the unlicensed radio frequency spectrum band, while also complying with established rules for spectrum access. Coordination may be required to ensure that the unlicensed radio frequency spectrum band can be used effectively.

  [0007] The present disclosure relates to, for example, one or more improved systems, methods, and / or devices for wireless communications, and more particularly, downlink coordination when accessing unlicensed radio frequency spectrum bands. The present invention relates to multipoint (CoMP) transmission. According to some aspects, a base station may perform a contention procedure, such as a clear channel assessment (CCA) procedure for accessing an unlicensed radio frequency spectrum band. The base station may determine a CCA state that indicates whether it has won contention for a period of time and may communicate the CCA state to other base stations in the CoMP cooperating set. Based on the CCA state exchanged between base stations in the CoMP cooperating set, coordinated communication with one or more of the other base stations in the CoMP cooperating set that has won contention for the time period is made available to the UE. Can be started. For example, the CCA state exchanged between base stations may include, for example, whether the base station has won contention for a channel in the unlicensed radio frequency spectrum band and channel state information (CSI). The CSI may include, for example, a rank indicator (RI) for use by one or more other base stations in the CoMP cooperating set.

  [0008] According to a first set of illustrative examples, a method for wireless communication by a base station of a CoMP cooperating set of base stations in a wireless communication network is for access to an unlicensed radio frequency spectrum band. Performing a Clear Channel Assessment (CCA) procedure to compete, determining a CCA state that indicates whether the contention for a period of time has been won, and determining the CCA state to one or more in the CoMP cooperating set Communicating to other base stations. In some examples, the method initiates CoMP communication with a user equipment (UE) using one or more base stations in a CoMP cooperating set with a CCA state that has won contention for a time period. Can further include.

  [0009] In some examples, the method also includes one or more of one or more other base stations that indicate whether one or more other base stations have won contention for a time period. Receiving CCA status may be included. The time period may correspond to, for example, a time period for transmitting a radio frame comprising a plurality of subframes, and communication and reception may be performed during a CCA state notification time period of the radio frame. In some examples, initiating CoMP communication may be performed after a CCA state notification time period of a radio frame. In some examples, the CCA status notification time period may be determined based at least in part on the nature of the CCA procedure.

  [0010] In some examples, initiating CoMP communication may include transmitting a control channel to a UE by a base station of one or more base stations and of one or more base stations Transmitting one or more data channels to the UE by the remaining base stations. Additionally or alternatively, initiating CoMP communication may include initiating dynamic point selection (DPS) communication from a base station to a user equipment (UE) during at least a portion of a time period and one or more. Canceling DPS communication from the base station while one of the base stations is performing DPS communication with the UE. The time period or a part thereof may correspond to, for example, a CCA state notification time period of a radio frame, and stopping DPS communication from the base station stops wireless transmission to the UE and / or transmission bandwidth May include transmitting to one or more other UEs to maintain a width threshold. In some examples, a portion of the time period may correspond to a time period of the first radio frame, and suspending DPS communication from the base station may cause transmission to the UE during the second radio frame. Can include discontinuing.

  [0011] In some examples, the method may also include transferring a channel state information (CSI) report from the base station to one or more other base stations in the CoMP cooperating set. The CSI report may include, for example, a rank indicator (RI) for use by one or more other base stations in the CoMP coordination set. Such an RI is one or more base stations in a CoMP cooperating set when a subsequent CCA procedure of the base station fails and one or more other base stations win the contention of the subsequent CCA procedure. May be for use by. In some examples, the method may also cause one or more other CCA procedures to fail when one or more other base stations win a contention for subsequent CCA procedures. Transferring a reference RI for use by the base station from the base station to one or more other base stations in the CoMP cooperating set.

  [0012] According to another set of illustrative examples, an apparatus for wireless communication by a base station in a CoMP cooperating set of base stations in a wireless communication network competes for access to an unlicensed radio frequency spectrum band. Means for performing a clear channel assessment (CCA) procedure to determine, a means for determining a CCA state that indicates whether a contention for a period of time has been won, and a CCA state in the CoMP cooperating set. Or means for communicating to a plurality of other base stations.

  [0013] In some examples, the apparatus may include means for implementing one or more aspects of the first set of illustrative examples described above.

  [0014] According to another set of illustrative examples, an apparatus for wireless communication by a base station of a CoMP cooperating set of base stations in a wireless communication network includes a processor and memory in electronic communication with the processor. Instructions that are stored in memory, wherein the instructions perform a CCA procedure to compete for access to the unlicensed radio frequency spectrum band and indicate whether the contention for a period of time has been won. Determining the state and communicating the CCA state to one or more other base stations in the CoMP cooperating set can be performed by the processor.

  [0015] In some examples, the processor is configured to execute instructions stored in memory for implementing one or more aspects of the first set of exemplary examples described above. obtain.

  [0016] According to another set of illustrative examples, a non-transitory computer-readable medium storing computer-executable code for wireless communication by a base station in a CoMP cooperating set of base stations in a wireless communication network The code performs a CCA procedure to contend for access to the unlicensed radio frequency spectrum band, determines a CCA state that indicates whether the contention for a certain time period has been won, and sets the CCA state to the CoMP cooperating set. Executable by a processor to communicate with one or more other base stations within.

  [0017] In some examples, the code may be executable by a processor to implement one or more aspects of the first set of illustrative examples described above.

  [0018] According to a further set of illustrative examples, a method for wireless communication by a user equipment in a wireless communication network is based at least in part on a CCA procedure for access to an unlicensed radio frequency spectrum band. Determining whether one or more base stations in the CoMP cooperating set has won contention for a time period and receiving CoMP communications from one or more base stations in the CoMP cooperating set that has won the contention Can include.

  [0019] According to another set of illustrative examples, an apparatus for wireless communication by user equipment in a wireless communication network is based at least in part on a CCA procedure for access to an unlicensed radio frequency spectrum band. Means for determining whether one or more base stations in the CoMP cooperating set have won contention for a time period and CoMP communication from one or more base stations in the CoMP cooperating set that has won the contention For receiving.

  [0020] According to yet another set of illustrative examples, an apparatus for wireless communication by user equipment in a wireless communication network includes a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be based on a clear channel assessment (CCA) procedure for access to unlicensed radio frequency spectrum bands, wherein one or more base stations in the CoMP cooperating set Determining whether the contention was won can be performed by the processor to cause the device to perform the determination and receiving the CoMP communication from one or more base stations in the CoMP cooperating set that has won the contention.

  [0021] According to yet another set of illustrative examples, a non-transitory computer-readable medium storing computer-executable code for wireless communication in a wireless communication network, wherein the code is an unlicensed radio frequency spectrum band Determining whether one or more base stations in the CoMP cooperating set won contention for the time period based on at least in part the CCA procedure for access to and in the CoMP cooperating set that won the contention Executable by a processor to receive CoMP communications from one or more base stations.

  [0022] Further scope of the applicability of the described methods and apparatus will become apparent from the following detailed description, claims, and drawings. Since various changes and modifications within the spirit and scope of the mode for carrying out the invention will become apparent to those skilled in the art, the mode for carrying out the invention and specific examples are given by way of illustration only.

  [0023] A further understanding of the nature and advantages of the present invention may be obtained by reference to the following drawings. In the appended figures, similar components or features may have the same reference label. In addition, various components of the same type can be distinguished by following the reference label with a dash and a second label that distinguishes between similar components. Where only the first reference label is used herein, the description applies to any one of similar components having the same first reference label, regardless of the second reference label. Is possible.

[0024] FIG. 2 is a block diagram conceptually illustrating an example of a wireless communication system in accordance with aspects of the present disclosure. [0025] FIG. 6 is a block diagram conceptually illustrating an example deployment scenario for using LTE in an unlicensed radio frequency spectrum band, in accordance with aspects of the present disclosure. [0026] FIG. 6 is a block diagram conceptually illustrating an example of base stations in a CoMP cooperating set according to aspects of this disclosure. [0027] A block conceptually illustrating an example of an eNB in a CoMP cooperating set in consecutive contention periods in which different eNBs in the CoMP cooperating set win contention for radio frequency spectrum bands in a continuous contention period according to aspects of this disclosure. Figure. FIG. 4 is a block diagram conceptually illustrating an example of an eNB in a CoMP cooperating set in successive contention periods that wins contention for a radio frequency spectrum band in a continuous contention period in which different eNBs in the CoMP cooperating set are continuous, according to aspects of this disclosure. [0028] FIG. 7 is a flowchart conceptually illustrating an example of a method for CoMP communication in a contention-based radio frequency spectrum band according to aspects of the disclosure. [0029] FIG. 7 is a block diagram conceptually illustrating an example of radio subframes and associated resource blocks transmitted by different base stations in a dynamic point selection CoMP scheme according to aspects of this disclosure. [0030] FIG. 7 is a block diagram conceptually illustrating an example of radio subframes and associated resource blocks transmitted by different base stations in a joint transmission CoMP scheme according to aspects of this disclosure. [0031] FIG. 7 conceptually illustrates a reference CSI process and a dependent CSI process for reference cells and subordinate cells in a CoMP cooperating set according to aspects of this disclosure. [0032] FIG. 7 is a block diagram conceptually illustrating a device, such as an eNB or a UE, for use in wireless communications in accordance with aspects of the present disclosure. 1 is a block diagram conceptually illustrating a device, such as an eNB or a UE, for use in wireless communications in accordance with aspects of the present disclosure. [0033] FIG. 7 is a block diagram conceptually illustrating a design of a UE according to an aspect of the disclosure. [0034] FIG. 6 is a block diagram conceptually illustrating a design of a base station according to aspects of the disclosure. [0035] FIG. 6 is a block diagram conceptually illustrating an example of a UE and a base station according to aspects of the disclosure. [0036] FIG. 10 is a flowchart conceptually illustrating an example of a method of wireless communication, according to an aspect of the disclosure. [0037] FIG. 9 is a flowchart conceptually illustrating an example of a method of wireless communication, according to an aspect of the disclosure. [0038] FIG. 7 is a flowchart conceptually illustrating an example of a method of wireless communication according to an aspect of the disclosure. [0039] FIG. 9 is a flowchart conceptually illustrating an example of a method of wireless communication according to an aspect of the disclosure.

  [0040] Describes techniques in which unlicensed radio frequency spectrum bands may be used for cellular communications (eg, Long Term Evolution (LTE) communications). LTE communications over an unlicensed radio frequency spectrum band may be referred to herein as extended LTE communications in an unlicensed radio frequency spectrum band. LTE communications over licensed radio frequency spectrum bands may be referred to herein as LTE communications.

  [0041] As data traffic increases in cellular networks, expanded data transmission capacity opportunities may be provided to cellular operators by offloading at least some data traffic to unlicensed radio frequency spectrum bands. Prior to acquiring channel access and transmitting using an unlicensed radio frequency spectrum band, the transmitting device may, in some deployments, use a listen before talk (LBT) procedure to acquire channel access. Can be implemented. Such an LBT procedure can be used in contention based access to a radio frequency spectrum band to verify that the radio frequency spectrum band is not currently utilized by another node or device, Clear channel assessment (CCA) may be included to determine if it is possible. If it is determined that the channel is not available, CCA may be performed again later. In addition, the use of unlicensed radio frequency spectrum bands allows access points of the same or different operator deployments that use the same or different techniques to access the unlicensed radio frequency spectrum bands to coexist within the unlicensed radio frequency spectrum bands Coordination may be required to ensure that.

  [0042] In some cases, coexistence may be enabled by coordination of CCA performed by different devices or nodes in different operator deployments that wish to access unlicensed radio frequency spectrum bands. In some of the CCA coordination methods, CCA may be coordinated to occur during a predetermined period of time between multiple devices or nodes in an operator deployment that may wish to access unlicensed radio frequency spectrum bands. For example, a time period during which multiple coordinated base stations may perform CCA during channel access for unlicensed radio frequency spectrum bands may be identified. Such cooperation results in a synchronization system in which nodes or devices seek access and transmit radio frequency signals in a synchronous manner.

  [0043] In coordinated multipoint (CoMP) transmission, as described above, two or more base stations may transmit data to the UE. Such CoMP transmissions transmit data to UEs at different times at different base stations (eg, each different base station may be assigned one or more time slots for transmission during a period of time). One or more of several CoMP transmission schemes may be used, including dynamic point selection (DPS) and joint transmission (JT) in which two or more base stations transmit data to the UE simultaneously. However, if CoMP may be desired to be used for a device using a contention-based radio frequency spectrum band, which of the two or more base stations wins the competition and uses the radio frequency spectrum band There may be uncertainty related to whether access can be gained for transmission. The present disclosure provides various techniques for employing CoMP transmission in a contention-based radio frequency spectrum band.

  [0044] According to various aspects of the present disclosure, communication by a base station in a CoMP coordinated set of base stations allows any of a number of base stations to access a channel in a radio frequency spectrum band. To establish whether the contention was won, the coordinated CCA procedure may be followed to communicate with one or more other base stations. CoMP transmission may then be coordinated between base stations that have won the contention. For example, the base station may implement a CCA procedure for access to unlicensed radio frequency spectrum bands. The base station may determine a CCA state that indicates whether it has won contention for a period of time and may communicate the CCA state to other base stations in the CoMP cooperating set. Based on the CCA state exchanged between base stations in the CoMP cooperating set, cooperative communication with two or more of the base stations in the CoMP cooperating set that has won contention for the time period is initiated to the UE Can be done. The CCA state exchanged between base stations may include, for example, whether the base station has won contention for a channel in the unlicensed radio frequency spectrum band and channel state information (CSI). The CSI may include, for example, a rank indicator (RI) for use by one or more other base stations in the CoMP cooperating set.

  [0045] The techniques described herein may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other systems. The terms “system” and “network” are often used interchangeably. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA). CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Release 0 and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is usually called CDMA2000 1xEV-DO, high-speed packet data (HRPD), and the like. UTRA includes wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM). The OFDMA system includes wireless devices such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, and Flash-OFDMA. Technology can be implemented. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS). 3GPP® Long Term Evolution (LTE) and LTE Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP). CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies. However, in the following description, an LTE system is described as an example, and LTE terminology is used in most of the following description, but the present technique is applicable to other than LTE application examples.

  [0046] Accordingly, the following description is provided by way of example and is not intended to limit the scope, applicability, or configuration set forth in the claims. Changes may be made in the function and configuration of the elements described without departing from the spirit and scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For example, the described methods may be performed in a different order than the described order, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in other examples.

  [0047] The term "wireless wide area network" or "WWAN" as used herein and in the appended claims refers to a cellular wireless network. Examples of WWAN include LTE network, UMTS network, CDMA2000 network, GSM / EDGE network, 1x / EV-DO network, and the like. In some examples, the WWAN may be referred to as a “radio access network”.

  [0048] The term "wireless local area network" or "WLAN" as used herein and in the appended claims refers to a non-cellular wireless network. WLAN examples, for example, conform to the IEEE 802.11 (“Wi-Fi”) standard family that can transmit using unlicensed radio frequency spectrum bands in the 5 GHz band according to established dynamic frequency selection (DFS) rules There is a wireless network to do.

  [0049] FIG. 1 illustrates a block diagram conceptually illustrating an example of a wireless communication system 100 in accordance with aspects of the present disclosure. The wireless communication system 100 includes a plurality of base stations (eg, access points, eNBs, or WLAN access points) 105, several user equipments (UEs) 115, and a core network 130. Some of the base stations 105 are under the control of a base station controller (not shown), which in various examples may be part of the core network 130 or some base stations 105 (eg, access points or eNBs). To communicate with the UE 115. Base station 105 may communicate control information and / or user data with core network 130 via backhaul link 132. In an example, base stations 105 may communicate directly or indirectly with each other via backhaul link 134, which may be either a wired or wireless communication link. The wireless communication system 100 may support operation on multiple carriers (waveform signals of different frequencies). A multi-carrier transmitter can transmit modulated signals simultaneously on multiple carriers. For example, each communication link 125 may be a multi-carrier signal modulated according to the various radio technologies described above. Each modulated signal may be sent on a different carrier and may carry control information (eg, reference signal, control channel, etc.), overhead information, data, etc.

  [0050] Base station 105 may communicate wirelessly with UE 115 via one or more base station antennas. Each of the base station 105 sites may provide communication coverage for a respective coverage area 110. In some examples, the base station 105 is a transceiver base station, a radio base station, a radio transceiver, a basic service set (BSS), an extended service set (ESS), a node B, an eNodeB, a home node B, a home enode. May be referred to as B, or some other suitable term. The coverage area 110 for the base station may be divided into sectors that constitute only a portion of the coverage area (not shown). The wireless communication system 100 may include different types of base stations 105 (eg, macro base stations, micro base stations, and / or pico base stations). Base station 105 may also utilize different radio technologies such as cellular and / or WLAN radio access technologies. Base stations 105 may be associated with the same or different access networks or operator deployments. The coverage areas of different base stations 105 that include the same or different types of base station 105 coverage areas, that utilize the same or different radio technologies, and / or belong to the same or different access networks may overlap.

  [0051] In an example, the wireless communication system 100 is an LTE / LTE-A communication system (or network) that supports one or more LTE in a contention-based radio frequency spectrum band mode of operation or deployment scenario, According to these examples, a contention-based channel access procedure coordinated between base station 105 and UE 115 that can be managed by CCA coordination manager 140 may be employed. In an example, the wireless communication system 100 may support wireless communication using an unlicensed radio frequency spectrum band and access technology, or using an access technology different from the licensed radio frequency spectrum band and LTE / LTE-A. In an LTE / LTE-A network communication system, the term evolved Node B (eNB) may be used, for example, to describe the base station 105. The wireless communication system 100 may be a heterogeneous LTE / LTE-A network in which different types of base stations provide coverage for various geographic regions. For example, each base station 105 may provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. Small cells such as pico cells, femto cells, and / or other types of cells may include low power nodes or LPNs. A macro cell may, for example, cover a relatively large geographic area (eg, a few kilometers in radius) and allow unrestricted access by UEs 115 subscribed to network provider services. A pico cell, for example, will cover a relatively small geographic area and may allow unrestricted access by UEs 115 subscribing to network provider services. A femtocell will also cover, for example, a relatively small geographic area (eg, home), and UE 115 (eg, a limited subscriber group (CSG)) associated with the femtocell in addition to unrestricted access. Limited access by a UE in a home, a UE for a user at home, etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a pico cell may be referred to as a pico eNB. Also, an eNB for a femto cell may be referred to as a femto eNB or a home eNB. An eNB may support one or multiple (eg, two, three, four, etc.) cells.

  [0052] The core network 130 may communicate with an eNB or other base station 105 via a backhaul 132 (eg, an S1 interface, etc.). Base stations 105 may also communicate with each other directly or indirectly, for example, via backhaul link 134 (eg, an X2 interface, etc.) and / or via backhaul link 132 (eg, through core network 130). . The wireless communication system 100 may support synchronous or asynchronous operation. For synchronous operation, the eNB may have similar frame timing and transmissions from different eNBs may be approximately aligned in time. For asynchronous operation, eNBs may have different frame timings and transmissions from different eNBs may not be time aligned. The techniques described herein may be used for either synchronous or asynchronous operations.

  [0053] The UEs 115 are distributed throughout the wireless communication system 100, and each UE 115 may be fixed or mobile. UE 115 may also be used by those skilled in the art for mobile stations, subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile It may be referred to as a terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term. UE 115 is a cellular phone, personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, tablet computer, laptop computer, cordless phone, wearable item such as watch or glasses, wireless local loop (WLL) station, etc. possible. UE 115 may be able to communicate with macro eNBs, pico eNBs, femto eNBs, relays, and the like. UE 115 may also be able to communicate on different access networks, such as a cellular or other WWAN access network, or a WLAN access network.

  [0054] The communication link 125 shown in the wireless communication system 100 may include an uplink (UL) transmission from the UE 115 to the base station 105 and / or a downlink (DL) transmission from the base station 105 to the UE 115. Downlink transmissions are sometimes referred to as forward link transmissions, and uplink transmissions are sometimes referred to as reverse link transmissions. Downlink transmission may be performed using a licensed radio frequency spectrum band, an unlicensed radio frequency spectrum band, or both. Similarly, uplink transmission may be performed using a licensed radio frequency spectrum band, an unlicensed radio frequency spectrum band, or both.

  [0055] The UE 115 may collaboratively communicate with multiple base stations 105, eg, via multiple input multiple output (MIMO), coordinated multipoint (CoMP), or other schemes. Can be configured. MIMO techniques use multiple antennas on the base station and / or multiple antennas on the UE to utilize a multipath environment to transmit multiple data streams. CoMP may include techniques for coordinated transmission and reception by several base stations to increase network and spectrum utilization and improve overall transmission quality for the UE, as described above. . CoMP techniques may utilize backhaul links 132 and / or 134 for communication between base stations 105 to coordinate control plane communication and user plane communication for UE 115. Cooperative areas for CoMP may include, for example, uniform deployment utilizing intra eNB CoMP or inter eNB CoMP. In various examples described herein, a base station 105 in a CoMP coordination area may be referred to as a CoMP coordination set.

  [0056] As described above, various deployments may use unlicensed radio frequency spectrum bands for CoMP. Such CoMP transmission consists of dynamic point selection (DPS) in which different base stations transmit data to the UE at different times and joint transmission (JT) in which two or more base stations transmit data to the UE simultaneously. One or more of several CoMP schemes may be used. According to various aspects, the first base station 105 in the CoMP cooperating set may determine which base station 105 in the CoMP cooperating set has won contention for channel access in the unlicensed radio frequency spectrum band. Following the procedure, one or more other base stations 105 in the coordinated set may be communicated. CoMP transmission may then be coordinated between the base stations 105 that have won the contention, as described in more detail below.

  [0057] In some examples of the wireless communication system 100, various deployment modes for LTE in a contention-based radio frequency spectrum band may cause LTE downlink capacity in the licensed radio frequency spectrum band to be turned off in the unlicensed radio frequency spectrum band. An auxiliary downlink mode that can be loaded, a carrier aggregation mode in which both LTE downlink capacity and LTE uplink capacity can be offloaded from a licensed radio frequency spectrum band to an unlicensed radio frequency spectrum band, and a base station (eg, eNB) LTE downlink communication and LTE uplink communication with the UE may be supported including a standalone mode in which it may be performed in an unlicensed radio frequency spectrum band. Each of the different modes may operate according to frequency division duplex (FDD) or time division duplex (TDD). An OFDMA communication signal may be used in communication link 125 for LTE downlink transmission in the unlicensed radio frequency spectrum band and / or in the licensed radio frequency spectrum band, and the SC-FDMA communication signal may be in the unlicensed radio frequency spectrum band and / or Or it may be used in the communication link 125 for LTE uplink transmission in the licensed radio frequency spectrum band. Transmissions using the unlicensed radio frequency spectrum band may be carried using one or more carrier frequencies in the frequency band. The frequency band may be divided into multiple carrier frequencies, for example, and each carrier frequency may have the same bandwidth or a different bandwidth. For example, each carrier frequency can occupy 20 MHz of the 5 GHz frequency band.

  [0058] In some deployments, as described above, a device seeking access to an unlicensed radio frequency spectrum band has the unlicensed radio frequency spectrum band available, ie, one unlicensed radio frequency spectrum band. Or it may be necessary to verify that it is not already in use by several other devices. Thus, prior to accessing the unlicensed radio frequency spectrum band, the device may perform a contention-based channel access procedure, also referred to as a listen-before-talk (LBT) procedure, to gain channel access. For example, the CCA procedure can be used to determine the availability of unlicensed radio frequency spectrum bands. Performing the CCA procedure may include checking that the unlicensed radio frequency spectrum band is not specifically occupied prior to initiating access. In some examples, CCA opportunities may be coordinated across multiple base stations 105 and may occur at periodic intervals, such as every 10 milliseconds (ms). A transmitting entity, such as base station 105, desires channel access and may perform a CCA procedure to determine whether a particular carrier frequency in the unlicensed radio frequency spectrum band is occupied. If a particular carrier frequency in the unlicensed radio frequency spectrum band is occupied, the base station 105 waits until the next CCA opportunity before trying again to access the channel on the associated carrier frequency. In a deployment that provides a CCA opportunity once every 10 ms, the base station 105 will have to wait 10 ms before attempting to access the channel. Similarly, UE 115 may wish to transmit uplink data to base station 105 using an unlicensed radio frequency spectrum band and may similarly perform CCA procedures. In some examples, an enhanced CCA (eCCA) procedure may be used to determine the availability of unlicensed radio frequency spectrum bands. In contrast to the LBT protocol (LBT-FBE) configured for frame-based equipment where the base station performs one CCA procedure per radio frame, the eCCA procedure is a random number of N CCA procedures. May be accompanied by implementation. The eCCA procedure implemented in connection with the LBT protocol configured for load-based equipment (LBT-LBE) is compared to a single CCA procedure implemented in connection with the LBT-FBE protocol (eg, And) may provide the base station or UE with a better opportunity to gain access to the unlicensed radio frequency spectrum band.

  [0059] In some examples, as described above, each of the base stations 105 in the CoMP cooperating set is pre-configured in a contention-based procedure for access to a radio frequency spectrum band (eg, an unlicensed radio frequency spectrum band). The CCA procedure may be performed at a defined time. A base station 105 that does not acquire a radio frequency spectrum band channel during the first CCA procedure then waits for a defined time period for the next coordinated CCA opportunity. A base station 105 that acquires a radio frequency spectrum band channel may then transmit radio signals using the radio frequency spectrum band.

  [0060] FIG. 2 is a block diagram conceptually illustrating an example deployment scenario for using LTE in an unlicensed radio frequency spectrum band in accordance with aspects of the present disclosure. The wireless communication system 200 illustrates an example of an auxiliary downlink mode, a carrier aggregation mode, and a stand-alone mode for between an eNB 205 and a UE 215 in an LTE network that supports LTE in a contention-based radio frequency spectrum band. Yes. The wireless communication system 200 may be an example of a portion of the wireless communication system 100 described with respect to FIG. Moreover, eNB 205 may be an example of one of base stations 105 of FIG. 1, and UE 215 may be an example of UE 115 described with respect to FIG.

  [0061] In an example of a supplemental downlink (SDL) mode in the wireless communication system 200, the eNB 205 may transmit an OFDMA communication signal to the UE 215 using the downlink 220. In the example of FIG. 2, downlink 220 may be associated with a frequency in an unlicensed radio frequency spectrum band. The eNB 205 may transmit the OFDMA communication signal to the same UE 215 using the bidirectional link 225, and may receive the SC-FDMA communication signal from the UE 215 using the bidirectional link 225. Bidirectional link 225 may be associated with a frequency in the licensed radio frequency spectrum band. The downlink 220 in the unlicensed radio frequency spectrum band and the bidirectional link 225 in the licensed radio frequency spectrum band can operate simultaneously. Downlink 220 may provide downlink capacity offload to eNB 205. In some examples, downlink 220 may be used for unicast services (eg, addressed to one UE) or for multicast services (eg, addressed to several UEs). . This scenario may occur for any service provider (eg, a traditional mobile network operator or MNO) that needs to use a licensed radio frequency spectrum band to alleviate some of the traffic and / or signaling congestion.

  [0062] In an example of a carrier aggregation (CA) mode in wireless communication system 200, eNB 205 may send an OFDMA communication signal to UE 215-a using bidirectional link 230, and SC using bidirectional link 230. -FDMA communication signals may be received from the same UE 215-a. In the example of FIG. 2, the bi-directional link 230 may be associated with a frequency in the unlicensed radio frequency spectrum band. The eNB 205 may also transmit OFDMA communication signals to the same UE 215-a using the bidirectional link 235 and may receive SC-FDMA communication signals from the same UE 215-a using the bidirectional link 235. Bidirectional link 235 may be associated with a frequency in the licensed radio frequency spectrum band. Bidirectional link 230 may provide eNB 205 with downlink capacity and uplink capacity offload. Like the auxiliary downlink described above, this scenario is for any service provider (eg, MNO) that needs to use a licensed radio frequency spectrum band to alleviate some of the traffic and / or signaling congestion. Can occur. The bi-directional link 230 may operate using TDD communication, according to some examples. When both eNB 205 and UE 215-a transmit data using bidirectional link 230, each performs LBT procedures prior to transmitting data using bidirectional link 230 over the unlicensed radio frequency spectrum band. Each may implement both a first CCA procedure and a second CCA procedure for access to the radio frequency spectrum band channel.

  [0063] In an example of a stand-alone (SA) mode in wireless communication system 200, eNB 205 may transmit an OFDMA communication signal to UE 215-b using bi-directional link 240 and associate it with a frequency in an unlicensed radio frequency spectrum band. An SC-FDMA communication signal may be received from the same UE 215-b using a bi-directional link 240 that may be used. This example and the example provided above are presented for illustration, and there may be other similar operating modes or deployment scenarios that combine LTE and LTE in the unlicensed radio frequency spectrum band for capacity offload. As explained above, service providers that can benefit from the capacity offload provided by using unlicensed radio frequency spectrum bands can be conventional MNOs that use licensed radio frequency spectrum bands. For these service providers, the operational configuration is a bootstrap mode (eg, auxiliary) that uses a primary component carrier (PCC) on the licensed radio frequency spectrum band and a secondary component carrier (SCC) on the unlicensed radio frequency spectrum band. Downlink, carrier aggregation).

  [0064] In SDL mode, control for LTE in the unlicensed radio frequency spectrum band may be transported over the LTE uplink (eg, the uplink portion of bi-directional link 225) in the licensed radio frequency spectrum band. One reason for providing downlink capacity offload is that data demand is largely driven by downlink consumption. Moreover, in this mode, the UE 215 is not transmitting in the unlicensed radio frequency spectrum band, so the regulatory impact may be small.

  [0065] In CA mode, data and control may be communicated in LTE (eg, bi-directional link 235) using licensed radio frequency spectrum bands, while data uses unlicensed radio frequency spectrum bands ( For example, bi-directional link 230) may be communicated. Carrier aggregation mechanisms supported when using unlicensed radio frequency spectrum bands are hybrid frequency division duplex-time division duplex (FDD-TDD) carrier aggregation, or TDD-TDD carrier aggregation with different symmetries across component carriers. Can fall into the category.

  [0066] In any of the various modes of operation, communications may be transmitted on one or more carrier frequencies in an unlicensed radio frequency spectrum band. According to various examples, as described above, the communication can be transmitted according to a TDD technique. As will be appreciated, some subframes in TDD communications may include downlink data, and some subframes may include uplink data.

  [0067] FIG. 3 is a block diagram conceptually illustrating an example of base stations in a CoMP cooperating set according to aspects of this disclosure. In this example, a portion of a wireless communication system 300 is shown, where a plurality of eNBs 305-a, 305-b, and 305-c are respectively covered coverage areas 310-a, 310-b, and 310. -C may be present. The wireless communication system 300 may be an example of a portion of the wireless communication system 100 and / or 200 described with respect to FIG. 1 and / or FIG. Moreover, eNB 305 may be an example of the base station of FIG. 1 and / or FIG. 2 and / or eNB 105 and / or 205, and UE 315 may be UE 115 and / or described with respect to FIG. 1 and / or FIG. Or it may be an example of 215. In this example, each eNB 305 may communicate with UE 315 using a channel in an unlicensed radio frequency spectrum band. According to some deployments, eNBs 305 may be coordinated and contend for the channel on each synchronization frame during coordinated contention periods between eNBs 305.

  [0068] In various aspects of this disclosure, the eNB 305 (eg, eNB 305-a, eNB 305-b, and eNB 305-c) may form a CoMP coordination set and may perform CoMP transmission to the UE 315. For example, a CoMP cooperating set eNB 305 may perform a cooperative contention procedure such as a clear channel assessment (CAA) procedure or an enhanced CCA (eCCA) to access an unlicensed radio frequency spectrum band. Each eNB 305 in the CoMP cooperating set may determine a CCA state that indicates whether it has won contention for a period of time. eNBs 305 may communicate CCA states with each other (eg, eNBs 305-a may communicate their CCA states to eNBs 305-b and / or eNBs 305-c). Based on the CCA state exchanged between eNBs 305 in the CoMP cooperating set, cooperative communication with two or more of the eNBs 305 in the CoMP cooperating set that have won for the time period may be initiated for the UE 315. For example, eNB 305-a and eNB 305-c may win contention and gain access to unlicensed radio frequency spectrum bands, eNB 305-b may not win contention, and access to unlicensed radio frequency spectrum bands Does not have The eNB 305-a and the eNB 305-c may start CoMP communication with the UE 315.

  [0069] In various examples, the CoMP transmission performed by the eNB 305 may include one or more CoMP transmission schemes and control techniques established for LTE / LTE-A. For example, an eNB 305 in a CoMP cooperating set may employ cross-cell control for dynamic point selection (DPS), where control information may be provided by eNB 305-a, for example, data may be sent to other eNBs 305-b. And / or may be provided by the eNB 305-c. In such cases, dynamic rate matching may be signaled via a control channel established between eNB 305-a and UE 315. In another example, the eNB 305 of the CoMP cooperating set receives a demodulation reference signal (DM-RS), a channel state information reference signal (CSI-RS), and a common reference signal (CRS: A quasi-colocated linkage between different reference signals from different eNBs 305, such as a common reference signal, may be provided. Such a reference signal may provide timing, frequency tracking, and / or channel estimation information for eNB 305 in the CoMP cooperating set. UE 315 may measure various parameters from one or more of the reference signals from each eNB 305 and may report the measurements to eNB 305-a, for example. In some examples, the UE 315 may be configured for a set of virtual cell IDs for one or more reference signals such as, for example, CSI-RS or DM-RS. Such a virtual cell ID may provide, for example, a common CRS location, CSI-RS configuration, and PDSCH start symbol. In other examples, one or more of eNBs 305-b or 305-c may inherit a rank indicator (RI) from eNB 305-a for use in multiple CSI processes.

  [0070] As described above, in an example where an eNB of a CoMP cooperating set utilizes contention-based access to a radio frequency spectrum band, such as an unlicensed radio frequency spectrum band, one or more eNBs Medium contention may not win, and other eNBs in the CoMP cooperating set may win the contention. Thus, the number of eNBs available in the cooperating set for CoMP communication can vary over consecutive time periods. 4A and 4B are conceptual illustrations of eNBs in a CoMP cooperating set in consecutive contention periods where different eNBs in the CoMP cooperating set win contention for radio frequency spectrum bands in consecutive contention periods according to aspects of this disclosure. FIG. The wireless communication system 400 of FIGS. 4A and 4B may be an example of portions of the wireless communication systems 100, 200, and / or 300 described with respect to FIGS. 1, 2, and / or 3. Moreover, the eNB 405 may be an example of one of the base stations or eNBs 105, 205, and / or 305 of FIGS. 1, 2, and / or the UE 415 may be the FIG. Or it may be an example of the UE 115, 215, and / or 315 described with respect to FIG.

  [0071] In this example, a portion of a wireless communication system 400 is shown in which multiple eNBs 405-a, 405-b, and 405-c may utilize CoMP communication with UE 415. In the example of FIG. 4A, each of the eNBs 405 may have won contention for channels in the radio frequency spectrum band during CCA period n and employs one or more CoMP techniques for communication with UE 415. Can do. As part of CoMP communication, eNB 405-a may communicate with UE 415 via communication link 425-a, eNB 405-b may communicate with UE 415 via communication link 425-b, and eNB 405-c may It may communicate with UE 415 via communication link 425-c. CoMP communication may include, for example, DPS transmission or JT CoMP transmission, or a combination thereof.

  [0072] However, before initiating transmission in CCA period n + 1, each eNB 405 may perform CCA or eCCA procedures to determine whether a channel is available for transmission in an unlicensed radio frequency spectrum band. carry out. In the example of FIG. 4B, eNB 405-a does not win contention for the channel, and both eNB 405-b and eNB 405-c win contention for the channel. Accordingly, the communication link 425-a does not exist in the CCA period n + 1. Accordingly, the eNB 405 in the CoMP cooperating set that can be used for CoMP communication is different between subframe n and subframe n + 1.

  [0073] In order to utilize CoMP communication in such cases, various aspects of the present disclosure can potentially serve eNBs in a CoMP cooperating set via communication resulting from contention to other eNBs in the CoMP cooperating set. Provide techniques for adapting to changes. FIG. 5 is a flowchart conceptually illustrating an example of a method for CoMP communication in a contention-based radio frequency spectrum band according to an aspect of the present disclosure. Method 500 will be described with reference to each of the base stations and / or access nodes such as eNBs 105, 205, 305, and / or 405 described with respect to FIG. 1, FIG. 2, FIG. 3, and / or FIG. In an example, an access node may execute one or more sets of code for controlling functional elements of the device to perform the functions described below.

  [0074] As shown in block 505, two or more base stations or eNBs may initiate a CoMP coordination set for wireless communication with the UE. A CoMP cooperating set may be initiated according to one or more CoMP techniques for such communication, as described in this disclosure. At block 510, each of the eNBs in the coordinated set may perform a CCA procedure to contend for access to the unlicensed radio frequency spectrum band. The CCA procedure may include, for example, an implementation of the CCA procedure by each eNB in a coordinated CCA slot within a coordinated CCA opportunity period that may be established, for example, by a CCA coordination manager of the core network. In some examples, each eNB in the coordination set may belong to the same operator, and the CCA slots for each eNB may be coordinated to occur simultaneously. Thus, if the channel is not occupied, each of the eNBs may win the contention for the channel, and other operators' eNBs with different CCA slots will not win the contention.

  [0075] At block 515, it is determined whether the eNB's CCA state indicates that it has won the contention. If the CCA state indicates that it has not won the contention, the eNB communicates the failed CCA state to other eNBs in the CoMP cooperating set, as shown in block 520. If it is determined at block 515 that the CCA state indicates that it has won the contention, the eNB starts transmission using the channel, as shown in block 525, and sets the successful CCA state within the CoMP coordinated set. Communicate with other eNBs. Such communication in CCA state may be signaled, for example, over a backhaul link between eNBs or may be signaled wirelessly between eNBs. In some examples, an information element that may include a CCA state to indicate whether the eNB has won contention for a communication period may be included in an existing communication between eNBs. At block 530, one or more CCA states may be received that may indicate whether the CCA was successful for one or more other eNBs in the CoMP cooperating set. According to some examples, a communication period related to CCA contention may correspond to an LTE radio frame, and an eNB in a CoMP cooperating set may receive a radio frame (eg, first few symbols or first subframe) CCA state information may be communicated during the state notification time period. During the state notification time period, the eNBs in the CoMP cooperating set communicate CCA states with other eNBs in the CoMP cooperating set to determine which of the eNBs in the cooperating set are available for transmission. Can do. If, at block 530, it is determined that no other eNB has won the competition, the eNB performs non-CoMP communication with the UE during the communication period, as shown at block 535. If it is determined at block 530 that one or more other eNBs have won the contention, the eNB may be within the CoMP coordinated set for the communication period after the state notification time period, as shown in block 540. CoMP communication for the UE with one or more other eNBs may be initiated. Following initiation of CoMP communication, eNBs in the coordinated set may transmit according to one or more CoMP techniques for communication with the UE for all or part of the remainder of the communication period. For example, the status notification time period may correspond to the first few symbols or the first subframe of the first subframe of the radio frame following the CCA procedure, and the CoMP communication may be initiated following the status notification time period. . In some examples, the CCA status notification time period may be determined based at least in part on the nature of the CCA procedure. At the end of the radio frame that may correspond to a communication period, the operations of method 500 may be repeated for subsequent communication periods.

  [0076] As explained above, various different CoMP techniques may be utilized by an eNB in a CoMP cooperating set. FIG. 6 is a block diagram 600 conceptually illustrating an example of radio subframes and related resource blocks transmitted by different base stations in a dynamic point selection (DPS) CoMP scheme in accordance with aspects of this disclosure. The wireless communication system of FIG. 6 may be an example of a portion of the wireless communication system 100, 200, 300, and / or 400 described with respect to FIGS. 1, 2, 3, and / or 4. Moreover, eNB 605 may be an example of one of base stations or eNBs 105, 205, 305, and / or 405 of FIGS. 1, 2, 3, and / or 4, and UE 615 may be 2, 3, and / or 4 may be examples of the UEs 115, 215, 315, and / or 415 described above.

  [0077] In this example, it may be determined that both eNB 605-a and eNB 605-b have won contention for the channel during contention period for access to the radio frequency spectrum band during subframe n. . Both eNB 605-a and eNB 605-b may cooperate to transmit different resource blocks during subframe n. In another example, eNB 605-a may coordinate to transmit all resource blocks during subframe n, or eNB 605-b may transmit all resource blocks during subframe n. Can cooperate (not shown). In the example of FIG. 6, the eNB 605-a may transmit the resource block 625 to the UE 615, and the eNB 605-b may transmit the resource block 630. However, in some examples, the access rules for contention-based radio frequency spectrum bands may maintain at least the minimum percentage of available transmission periods ( For example, it may need to be occupied for 80%). For example, while eNB 605-a is transmitting resource block 625, eNB 605-b may communicate with one or more other UEs, or to satisfy a minimum percentage occupancy, Spectral bands may be used to transmit relatively low power channel occupancy signals. The low power occupancy signal may include, for example, a channel usage beacon signal (CUBS) to maintain access to the channel. In another example, eNB 605-a and eNB 605-b may alternate contention periods during which eNB 605 transmits so that one eNB 605 maintains established channel occupancy rules for the radio frequency spectrum band Make it possible.

  [0078] Another CoMP technique that may be utilized alone or in conjunction with DPS is a joint transmission (JT) CoMP scheme that may be utilized by an eNB in a CoMP cooperating set. FIG. 7 is a block diagram 700 conceptually illustrating an example of radio subframes and related resource blocks transmitted by different base stations in a joint transmission CoMP scheme according to aspects of this disclosure. The wireless communication system of FIG. 7 may be an example of a portion of the wireless communication system 100, 200, 300, 400, and / or 600 described with respect to FIGS. 1, 2, 3, 4, and / or 6. Moreover, the eNB 705 can be an example of one of the base stations or eNBs 105, 205, 305, 405, and / or 605 of FIG. 1, FIG. 2, FIG. 3, FIG. 4, and / or FIG. UE 715 may be an example of UE 115, 215, 315, 415, and / or 615 described with respect to FIGS. 1, 2, 3, 4, and / or 6.

  [0079] In this example, it may be determined that both eNB 705-a and eNB 705-b have won contention for the channel during contention period for access to the radio frequency spectrum band during subframe n. . Both eNB 705-a and eNB 705-b may coordinate to transmit resource block 725 during subframe n. In the example of FIG. 7, both eNB 705-a and eNB 705-b may transmit resource block 725 at the same time. In such a case, both eNBs may maintain transmission occupancy rules for contention based radio frequency spectrum bands.

  [0080] When utilizing JT and / or DPS CoMP techniques, the UE 715 may perform various measurements, such as various CSI measurements, as described above. When performing CSI measurement, UE 715 may use, for example, the CSI reference signal from eNB 705-a as the reference CSI-RS, and measure based on information in reference CSI-RS to provide CSI information to eNB 705-b. Can be done. For example, the CSI-RS information may include a rank indicator (RI), and various measurements in CSI may be determined based on the RI value for the reference CSI-RS. Further, CSI based on CSI-RS from eNB 705-b, referred to as a subordinate CSI process, may include various values based on RI values for reference CSI-RS. However, in some cases, the CCA for the reference CSI process may fail, and thus the RI value for the subordinate CSI process may need to be established in such cases.

[0081] FIG. 8 is a diagram 800 that conceptually illustrates a reference CSI process and a dependent CSI process for reference cells and dependent cells in a CoMP cooperating set according to aspects of this disclosure. In this example, the reference CSI process may include a wideband CSI measurement (shown as WB in FIG. 8) and three subband CSI measurements (shown as SB in FIG. 8), where the subband measurement is a rank indicator of one. _Done for one cycle at the reporting interval for (M _RI ). In the example of FIG. 8, the dependent CSI process may also include wideband CSI measurements and three subband CSI measurements. However, the dependent CSI process may provide subband measurements for two cycles with a reporting interval for one rank indicator (M _RI ). According to an example, the dependent CSI process may inherit the initial RI value 820 from the reference CSI process at time T ₀ , as shown at 825, for the dependent CSI process wideband measurement as shown at 830, and It can be utilized for subband measurements as shown at 835. In this example, the reference eNB associated with the reference cell, may fail the CCA process at some time prior to time T _1, eNB associated with subordinate CSI process has successful CCA. Following time T ₁ , the dependent CSI process expects to inherit the updated RI value 840 from the reference CSI process for use in subsequent subband CSI measurements 845. The reference eNB may also be referred to as a serving eNB in some examples.

  [0082] However, because the reference eNB failed the CCA, the updated RI is not available. According to some examples, the dependent CSI process may make a determination that the CCA has failed at the reference eNB, and finally reports from the reference CSI process when the dependent eNB CCA succeeds following the failure of the reference eNB CCA. A modified RI820 may be used. In another example, the dependent CSI process may depend on a CSI subset restriction approach, where the RI value is established for use in the dependent CSI process. In yet another example, an eNB in a coordinated set may use a control channel that signals, for example, a “reference rank” when a reference eNB transmitting a CSI-RS for a reference CSI process fails a CCA, Can be signaled. As such, the dependent CSI process may determine CSI information for continued transmission with the UE.

  [0083] FIGS. 9A and 9B are block diagrams conceptually illustrating a device, such as an eNB or UE, for use in wireless communications, in accordance with aspects of the present disclosure. Referring initially to FIG. 9A, a block diagram 900 illustrates a device 905 for use in wireless communications, according to various examples. In some examples, the device 905 may be the base station or eNB 105, 205, 305, 405, 605, 705 and / or UE 115 described with respect to FIGS. 1, 2, 3, 4, 6, and / or 7. 215, 315, 415, 615, 715 may be an example of one or more aspects. Device 905 can also be a processor. Device 905 may include a receiver module 910, a CoMP module 920, and / or a transmitter module 930. Each of these components can be in communication with each other.

  [0084] The components of device 905 may be used individually or using one or more application specific integrated circuits (ASICs) adapted to perform some or all of the applicable functions in hardware. Can be implemented together. Alternatively, those functions may be performed on one or more integrated circuits by one or more other processing units (or cores). In other examples, other types of integrated circuits (eg, structured / platform ASICs, field programmable gate arrays (FPGAs), and other semi-custom ICs) that can be programmed in any manner known in the art. Can be used. The functionality of each unit may also be implemented in whole or in part using instructions embedded in memory that are formatted to be executed by one or more general purpose or application specific processors.

  [0085] In some examples, the receiver module 910 may receive radio frequency (RF) reception, such as an RF receiver operable to receive transmissions in a licensed radio frequency spectrum band and / or an unlicensed radio frequency spectrum band. Or may include it. Receiver module 910 may include one or more communication links 125, 220-240, and / or 425 of wireless communication systems 100, 200, and / or 400 described with respect to FIGS. 1, 2, and / or FIG. For receiving various types of data and / or control signals (ie, transmissions) over one or more communication links of a wireless communication system including licensed and unlicensed radio frequency spectrum bands Can be used.

  [0086] In some examples, the transmitter module 930 is an RF transmitter, such as an RF transmitter operable to transmit in a licensed radio frequency spectrum band and / or an unlicensed radio frequency spectrum band, or It can include it. The transmitter module 930 may include one or more communication links 125, 220-240, and / or 425 of the wireless communication systems 100, 200, and / or 400 described with respect to FIGS. 1, 2, and / or FIG. May be used to transmit various types of data and / or control signals (ie, transmissions) over one or more communication links of a wireless communication system.

  [0087] In some examples, the COMP module 920 may configure and / or implement coordinated CoMP communication with two or more eNBs. When the CoMP module 920 determines that an unlicensed radio frequency spectrum band should be used in communication, whether a CoMP coordination set has been established and one or more other eNBs in the CoMP coordination set are For example, it may be determined whether a contention based access to a channel in the radio frequency spectrum band has been won to establish CoMP communication, as described above with respect to FIGS.

  [0088] Referring now to FIG. 9B, a block diagram 950 illustrates a device 955 for use in wireless communications in accordance with various aspects of the present disclosure. In some examples, the device 955 may be the base station or eNB 105, 205, 305, 405, 605, 705 and / or UE 115 described with respect to FIGS. 1, 2, 3, 4, 6, and / or 7. 215, 315, 415, 615, 715 may be an example of one or more aspects. Device 955 can also be a processor. Device 955 may include a receiver module 912, a COMP module 922, and / or a transmitter module 932. Each of these components can be in communication with each other.

  [0089] The components of device 955 may be implemented individually or collectively using one or more ASICs adapted to perform some or all of the applicable functions in hardware. Alternatively, those functions may be performed on one or more integrated circuits by one or more other processing units (or cores). In other examples, other types of integrated circuits (eg, structured / platform ASICs, FPGAs, and other semi-custom ICs) that can be programmed in any manner known in the art can be used. The functionality of each unit may also be implemented in whole or in part using instructions embedded in memory that are formatted to be executed by one or more general purpose or application specific processors.

  [0090] In some examples, the receiver module 912 may be an example of the receiver module 910 of FIG. 9A. Receiver module 912 is or includes a radio frequency (RF) receiver, such as an RF receiver operable to receive transmissions in a licensed radio frequency spectrum band and / or an unlicensed radio frequency spectrum band. obtain. The RF receiver may include separate receivers for the licensed radio frequency spectrum band and the unlicensed radio frequency spectrum band. Separate receivers may optionally take the form of licensed RF spectrum band receiver module 914 and unlicensed RF spectrum band receiver module 916. The receiver module 912, including the licensed RF spectrum band receiver module 914 and the unlicensed RF spectrum band receiver module 916, is the wireless communication system 100, 200, and / or 400 described with respect to FIGS. 1, 2, and / or FIG. Through one or more communication links of a wireless communication system including licensed and unlicensed radio frequency spectrum bands, such as one or more communication links 125, 220-240, and / or 425 of Can be used to receive various types of data and / or control signals (ie, transmissions).

  [0091] In some examples, the transmitter module 932 may be an example of the transmitter module 930 of FIG. 9A. Transmitter module 932 may be or include an RF transmitter, such as an RF transmitter operable to transmit in a licensed radio frequency spectrum band and / or an unlicensed radio frequency spectrum band. The RF transmitter may include separate transmitters for the licensed radio frequency spectrum band and the unlicensed radio frequency spectrum band. Separate transmitters may optionally take the form of licensed RF spectrum band transmitter module 934 and unlicensed RF spectrum band transmitter module 936. The transmitter module 932 may be a wireless device, such as one or more communication links 125, 220-240, and / or 425 of the wireless communication systems 100, 200, and / or 400 described with respect to FIGS. It can be used to send various types of data and / or control signals (ie, transmissions) over one or more communication links of the communication system.

  [0092] The CoMP module 922 may be an example of the CoMP module 920 described with respect to FIG. 9A and may include a CCA state determination module 965, a CCA state communication module 975, and / or a CoMP coordination module 980. Each of these components can communicate with each other.

  [0093] In some examples, the CCA state determination module 965 determines whether the eNB has won contention according to a CCA procedure for accessing channels in a contention-based radio frequency spectrum band. The CCA procedure may be a procedure performed during a contention period coordinated among multiple eNBs and / or operators, as described above. The CCA state communication module 975 communicates with the eNB of the CoMP cooperating set to communicate the CCA state of the eNB and also to receive CCA states from one or more other eNBs in the CoMP cooperating set. Can do. The CoMP coordination module 980, in some examples, uses one or more CoMP techniques (eg, JT and / or DPS), and the eNB of the coordination set is described above, for example, with respect to FIGS. When such a CoMP transmission should be transmitted, one or more aspects of CoMP communication with other eNBs in the cooperative set, such as reference signal information, may be coordinated.

  [0094] FIG. 10 is a block diagram 1000 that conceptually illustrates a design of a UE, in accordance with aspects of the present disclosure. In FIG. 10, a block diagram 1000 illustrating a UE 1015 configured for CoMP using contention-based channel access in a radio frequency spectrum band is shown. The UE 1015 may have a variety of other configurations, such as a personal computer (eg, laptop computer, netbook computer, tablet computer, etc.), cellular phone, PDA, digital video recorder (DVR), Internet equipment, gaming console, electronic It can be included in a leader or the like or part of them. The UE 1015 may have a built-in power supply (not shown) such as a small battery to allow mobile operation. In some examples, the UE 1015 may be a UE or device 115, 215, 315, 415, 615, described with respect to FIGS. 1, 2, 3, 4, 6, 6, 7, 9A, and / or 9B. It may be an example of one or more of 715, 905 and / or 955. UE 1015 may be the base station, eNB or device 105, 205, 305, 405, 605, 705, 905 described with respect to FIGS. 1, 2, 3, 4, 6, 7, 9A and / or 9B. And / or may be configured to communicate with one or more of 955.

  [0095] The UE 1015 includes a processor module 1010, a memory module 1020, at least one transceiver module (represented by a transceiver module 1070), at least one antenna (represented by an antenna 1080), and / or a UE radio frequency (RF ) May include a spectral band module 1040. Each of these components may be in communication with each other directly or indirectly via one or more buses 1035.

  [0096] The memory module 1020 may include RAM and / or ROM. The memory module 1020, when executed, is configured to cause the processor module 1010 to perform various functions described herein to use LTE-based communication in licensed and / or unlicensed radio frequency spectrum bands. Computer readable, computer executable software (SW) code 1025 containing stored instructions may be stored. Alternatively, the software code 1025 may not be directly executable by the processor module 1010, but causes the UE 1015 to perform various UE functions described herein (eg, when compiled and executed). Can be configured.

  [0097] The processor module 1010 may include intelligent hardware devices such as CPUs, microcontrollers, ASICs, and the like. The processor module 1010 may process information received through the transceiver module 1070 and / or information to be sent to the transceiver module 1070 for transmission through the antenna 1080. The processor module 1010 may handle various aspects of using LTE-based communications in licensed and / or unlicensed radio frequency spectrum bands, including CoMP communications, alone or in conjunction with the UE RF spectrum band module 1040.

  [0098] The transceiver module 1070 may be configured to bi-directionally communicate with an eNB. The transceiver module 1070 may be implemented as one or more transmitter modules and one or more separate receiver modules. The transceiver module 1070 may support communication in at least one licensed radio frequency spectrum band and in at least one unlicensed radio frequency spectrum band. Transceiver module 1070 may include a modem configured to modulate the packet, provide the modulated packet to antenna 1080 for transmission, and demodulate the packet received from antenna 1080. Although UE 1015 may include a single antenna, there may be examples where UE 1015 may include multiple antennas 1080.

  [0099] According to the architecture of FIG. 10, the UE 1015 may further include a communication management module 1030. The communication management module 1030 may manage communication with various base stations or eNBs. Communication management module 1030 may be a component of UE 1015 that is communicating with some or all of the other components of UE 1015 via one or more buses 1035. Alternatively, the functionality of the communication management module 1030 may be implemented as a component of the transceiver module 1070, as a computer program product, and / or as one or more controller elements of the processor module 1010.

  [0100] The UE RF spectrum band module 1040 is a CoMP-related function or aspect described in FIGS. 1-9 related to using LTE-based communication in licensed and / or unlicensed contention-based radio frequency spectrum bands. May be configured to implement and / or control some or all of the above. For example, the UE RF spectrum band module 1040 may be configured to determine that two or more eNBs are transmitting in the CoMP coordinated set, may receive communications based on the determination, and / or various criteria A signal measurement may be provided. UE RF spectrum band module 1040 includes an LTE module 1045 configured to process LTE communications in an authorized radio frequency spectrum band, an LTE unlicensed module 1050 configured to process LTE communications in an unlicensed radio frequency spectrum band, and / Or UE CoMP module 1055 may be included. The UE CoMP module 1055 may determine that two or more eNBs are transmitting in the CoMP cooperating set, may receive communication based on the determination, and / or provide various reference signal measurements. UE RF spectral band module 1040 or portions thereof may include a processor and / or some or all of the functionality of UE RF spectral band module 1040 may be performed by and / or in connection with processor module 1010. Can be done.

  [0101] FIG. 11 is a block diagram conceptually illustrating a design of a base station according to an aspect of the present disclosure. In FIG. 11, a block diagram 1100 illustrating a base station 1105 configured for CoMP in connection with contention-based channel access in a radio frequency spectrum band is shown. In some examples, the base station 1105 can be the base station, eNB, or device 105, described with respect to FIGS. 1, 2, 3, 4, 6, 6, 7, 9A, and / or 9B. It may be an example of one or more aspects of 205, 305, 405, 605, 705, 905, and / or 955. Base station 1105 may be configured to implement at least some of the features and functions of CoMP described with respect to FIGS. Base station 1105 includes processor module 1110, memory module 1120, at least one transceiver module (represented by transceiver module 1155), at least one antenna (represented by antenna 1160), and / or base station radio frequency (RF ) May include a spectral band module 1170. Base station 1105 may also include one or both of base station communication module 1130 and network communication module 1140. Each of these components may communicate with each other directly or indirectly via one or more buses 1135.

  [0102] The memory module 1120 may include random access memory (RAM) and / or read only memory (ROM). The memory module 1120, when executed, includes various described herein for using LTE-based communication in licensed and / or unlicensed radio frequency spectrum bands, including performing CoMP related communications and measurements. Computer readable, computer executable software (SW) code 1125 may be stored that includes instructions configured to cause processor module 1110 to perform various functions. Alternatively, software code 1125 may not be directly executable by processor module 1110, but, for example, when compiled and executed, causes base station 1105 to perform various functions described herein. Can be configured.

  [0103] The processor module 1110 may include intelligent hardware devices, such as a central processing unit (CPU), microcontroller, ASIC, and the like. The processor module 1110 may process information received via the transceiver module 1155, the base station communication module 1130, and / or the network communication module 1140. The processor module 1110 can also transmit to the transceiver module 1155 for transmission via the antenna 1160 to the base station communication module 1130 for transmission to one or more other base stations or eNBs 1105-a and 1105-b. And / or may process information to be sent to the network communication module 1140 for transmission to the core network 1145, which may be an example of aspects of the core network 130 described with respect to FIG. The processor module 1110 alone or together with the base station RF spectrum band module 1170 includes LTE in licensed and / or unlicensed radio frequency spectrum bands, including implementation of CoMP related functions as described above with respect to FIGS. Various aspects of using base communication may be handled.

  [0104] The transceiver module 1155 may include a modem configured to modulate the packet, provide the modulated packet to the antenna 1160 for transmission, and demodulate the packet received from the antenna 1160. The transceiver module 1155 may be implemented as one or more transmitter modules and one or more separate receiver modules. The transceiver module 1155 may support communication in at least one licensed radio frequency spectrum band and in at least one unlicensed radio frequency spectrum band. The transceiver module 1155 may be, for example, one of the UEs or devices 115, 215, 315, 415, 615, 715 and / or 1015 described with respect to FIG. 1, FIG. 2, FIG. 4, FIG. One or more may be configured to communicate bi-directionally via antenna 1160. Base station 1105 may typically include multiple antennas 1160 (eg, an antenna array). Base station 1105 may communicate with core network 1145 through network communication module 1140. Base station 1105 may communicate with other base stations or eNBs, such as eNB 1105-a and / or 1105-b, which may be other base stations in the CoMP coordinated set, using base station communication module 1130.

  [0105] According to the architecture of FIG. 11, the base station 1105 may further include a communication management module 1150. Communication management module 1150 may manage communication with other base stations, eNBs and / or devices. Communication management module 1150 may communicate with some or all of the other components of base station 1105 via one or more buses 1135. Alternatively, the functionality of the communication management module 1150 may be implemented as a component of the transceiver module 1155, as a computer program product, and / or as one or more controller elements of the processor module 1110.

  [0106] The base station RF spectrum band module 1170 may implement and / or perform some or all of the base station functions or aspects described with respect to FIGS. 1-9 related to CoMP communications in licensed and / or unlicensed radio frequency spectrum bands. It can be configured to control. For example, the base station RF spectrum band module 1170 may be configured to support CCA operation according to coordinated contention intervals and to communicate CCA status with other base stations 1105-a and 1105-b. Base station RF spectrum band module 1170 is an LTE module 1175 configured to process LTE communications in the licensed radio frequency spectrum band, an LTE unlicensed module configured to process LTE communications in the unlicensed radio frequency spectrum band and CCA. 1180, and / or an unlicensed module 1185 configured to handle non-LTE communications in the unlicensed radio frequency spectrum band. Base station RF spectral band module 1170 may also include a base station CoMP module 1190 configured to provide, for example, any of the CoMP functions described with respect to FIGS. Base station CoMP module 1190 may be an example of a similar module (eg, module 920 and / or 922) described with respect to FIGS. 9A and / or 9B. Base station RF spectral band module 1170 or portions thereof may include a processor and / or some or all of the functionality of base station RF spectral band module 1170 may be associated with and / or associated with processor module 1110. Can be implemented.

  [0107] FIG. 12 is a block diagram conceptually illustrating an example of a UE and a base station according to aspects of the present disclosure. Base station 1205 and UE 1215 may be part of a wireless communication system 1200. The wireless communication system 1200 may represent aspects of the wireless communication system 100, 200, 300, 400, 600, and / or 700 of FIGS. 1, 2, 3, 4, 6, and / or 7. For example, the base station 1205 may be the base station described above with respect to FIGS. 1, 2, 3, 4, 6, 7, and / or 11, or the eNB 105, 205, 305, 405, 605, 705. , And / or 1105 may be an example of one or more of the UEs 1215, the UE 11515 described above with respect to FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 215, 315, 415, 615, 715, and / or 1015 may be one example.

[0108] Base station 1205 may be equipped with base station antennas 1234 _{1 to} 1234 _x , where x is a positive integer, and UE 1215 may be equipped with UE antennas 1252 _{1 to} 1252 _n . In wireless communication system 1200, base station 1205 may be able to send data simultaneously over multiple communication links. Each communication link may be referred to as a “layer”, and the “rank” of the communication link may indicate the number of layers used for communication. For example, in a 2 × 2 MIMO system where base station 1205 transmits two “layers”, the rank of the communication link between base station 1205 and UE 1215 is two.

[0109] At base station 1205, base station transmit processor 1220 may receive data from a base station data source and receive control information from base station processor 1240. The control information may be for PBCH, PCFICH, PHICH, PDCCH, etc. The data can be for PDSCH and the like. Base station transmit processor 1220 may process (eg, encode and symbol map) data and control information to obtain data symbols and control symbols, respectively. Base station transmit processor 1220 may also generate reference symbols for, for example, PSS, SSS, and cell specific reference signals. Base station transmission (TX) MIMO processor 1230 may perform spatial processing (eg, precoding) on the data symbols, control symbols, and / or reference symbols, if applicable, and transmit the output symbol stream to the base station. Modulators 1232 _{1 to} 1232 _x may be provided. Each base station modulator 1232 may process a respective output symbol stream (eg, for OFDM, etc.) to obtain an output sample stream. Each base station modulator 1232 may further process (eg, convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink (DL) signal. In one example, DL signal from the base station modulator 1232 ₁ ~1232 _x may be transmitted via the respective base station antennas 1234 ₁ ~1234 _x.

In [0110] UE1215, UE antenna 1252 ₁ ~1252 _n may receive the DL signal from the base station 1205 may provide a received signal 1254 to _{1 ~1254 n} each UE demodulator. Each UE demodulator 1254 may adjust (eg, filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator 1254 may further process input samples (eg, for OFDM, etc.) to obtain received symbols. UE MIMO detector 1256 may obtain received symbols from all UE demodulators 1254 _{1 to} 1254 _n and may perform MIMO detection on the received symbols, if applicable, to provide detected symbols. A UE receive (Rx) processor 1258 processes (eg, demodulates, deinterleaves, and decodes) the detected symbols, provides decoded data for UE 1215 to the data output, and provides decoded control information to UE processor 1280 or UE The memory 1282 may be provided.

[0111] On the uplink (UL), at the UE 1215, a UE transmit processor 1264 may receive and process data from the UE data source. UE transmit processor 1264 may also generate reference symbols for the reference signal. Symbols from UE transmit processor 1264, if applicable precoded by the UE transmits MIMO processor 1266, (e.g., such as for SC-FDMA) is further processed by the UE demodulator 1254 ₁ ~1254 _n, the base station The transmission parameters received from 1205 may be transmitted to base station 1205. At base station 1205, the UL signal from UE 1215 is received by base station antenna 1234, processed by base station demodulator 1232, detected by base station MIMO detector 1236, where applicable, and received by base station receive processor 1238. It can be further processed. Base station receive processor 1238 may provide decoded data for the base station to a data output and base station processor 1240. The components of UE 1215 are implemented individually or collectively using one or more application specific integrated circuits (ASICs) adapted to perform some or all of the applicable functions in hardware. obtain. Each of the mentioned modules may be a means for performing one or more functions related to the operation of the wireless communication system 1200. Similarly, components of base station 1205 can include one or more application specific integrated circuits (ASICs) adapted to implement some or all of the applicable functions in hardware, individually or collectively. Can be implemented using Each of the mentioned components may be a means for performing one or more functions related to the operation of the wireless communication system 1200.

  [0112] A communication network that may accommodate some of the various disclosed examples may be a packet-based network that operates according to a layered protocol stack. For example, communication at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP based. A radio link control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. The medium access control (MAC) layer may perform priority processing and multiplexing of the logical channel to the transport channel. The MAC layer may also use hybrid ARQ (HARQ) to perform retransmissions at the MAC layer to improve link efficiency. At the physical layer, transport channels can be mapped to physical channels.

  [0113] In one example, the base station 1205 determines that it has won a contention for a period of time, a means for performing a contention-based downlink channel access procedure for accessing a channel in an unlicensed radio frequency spectrum band. And means for communicating to the one or more other base stations in the CoMP cooperating set that the contention has been won. In one aspect, the means described above is configured to perform the functions provided by the means described above, the base station processor 1240 of the base station 1205, the base station memory 1242, the base station transmission processor 1220, the base station reception. Machine processor 1238, base station modulator / demodulator 1232, and base station antenna 1234. In an example, the UE 1215 can include means for determining that the serving base station has won a contention-based downlink channel access procedure for accessing a channel in the unlicensed radio frequency spectrum band, as well as the serving base station and the cooperative multi Means for receiving communications from one or more other base stations in a point (CoMP) coordinated set. The above-described means includes a UE processor 1280, UE memory 1282, UE transmit processor 1264, UE receiver processor 1258, UE receiver processor 1258, UE modulator / demodulator configured to perform the functions provided by the means described above. 1254, and UE antenna 1252.

  [0114] FIG. 13 is a flowchart conceptually illustrating an example method of wireless communication, according to an aspect of the disclosure. For clarity, the method 1300 is described with respect to the base station, eNB, or device described with respect to FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. Reference is made below to each of 105, 205, 305, 405, 605, 705, 905, 955, 1105 and / or 1205. In one example, the base station may execute one or more sets of codes for controlling the functional elements of the base station to perform the functions described below.

  [0115] At block 1305, a CCA procedure is performed to contend for access to the unlicensed radio frequency spectrum band. In some examples, performing the CCA procedure may include performing an enhanced clear channel assessment (eCCA) procedure. In some examples, multiple base stations of the same and / or different operators may be coordinated to implement contention based access to unlicensed radio frequency spectrum bands. The operations in block 1305 have been described with respect to FIG. 11, CoMP modules 920 and / or 922 associated with receiver modules 910 and 912 and transmitter modules 930 and 932, as described with respect to FIGS. It may be implemented using base station RF spectral band module 1170 associated with transceiver module 1155 and antenna 1160, and / or processor 1240 and related components described with respect to FIG.

  [0116] At block 1310, a CCA state is determined that indicates whether the contention for a period of time has been won. The operations in block 1310 may optionally include the CMP modules 920 and / or 922 associated with the receiver modules 910 and 912 and the transmitter modules 930 and 932 described with respect to FIGS. 9A and / or 9B, and the CCA described with reference to FIG. 9B. It may be implemented using the state determination module 965, the base station RF spectrum band module 1170 associated with the transceiver module 1155 and antenna 1160 described with respect to FIG. 11, and / or the processor 1240 and related components described with respect to FIG.

  [0117] At block 1315, the base station may communicate the CCA state to one or more other base stations in the CoMP cooperating set. The operations in block 1315 may optionally include CoMP modules 920 and / or 922 associated with transmitter modules 930 and 932 described with respect to FIGS. 9A and / or 9B, CCA state communication module 975 described with respect to FIG. 9B, FIG. May be implemented using the transceiver module 1155 and the base station RF spectrum band module 1170 associated with the antenna 1160 and / or the processor 1240 and related components described with respect to FIG.

  [0118] In optional block 1320, the base station may communicate with a user equipment (UE) using one or more other base stations in a CoMP cooperating set having a CCA state that is winning contention for the time period. CoMP communication can be started. The operations in block 1320 may optionally include CoMP modules 920 and / or 922 associated with receiver modules 910 and 912 and transmitter modules 930 and 932 described with respect to FIGS. 9A and / or 9B, and CoMP described with reference to FIG. 9B. Coordination module 980, base station RF spectrum band module 1170 associated with transceiver module 1155 and antenna 1160 described with respect to FIG. 11, and / or processor 1240 and related components described with respect to FIG.

  [0119] In this manner, method 1300 may provide wireless communication in which CoMP communication may be provided in a contention based channel access procedure. Note that method 1300 is only one implementation and the operation of method 1300 may be reordered or otherwise modified to allow other implementations.

  [0120] FIG. 14 is a flowchart conceptually illustrating an example of a method of wireless communication according to an aspect of the present disclosure. For clarity, the method 1400 is described with respect to the base station, eNB, or device described with respect to FIGS. 1, 2, 3, 4, 6, 7, 7, 9A, 9B, 11, and / or 12. Reference is made below to each of 105, 205, 305, 405, 605, 705, 905, 955, 1105 and / or 1205. In one example, the base station may execute one or more sets of codes for controlling the functional elements of the base station to perform the functions described below.

  [0121] At block 1405, a CCA procedure is performed to contend for access to the unlicensed radio frequency spectrum band. In some examples, performing a CCA procedure may include performing an eCCA procedure. In some examples, multiple base stations of the same and / or different operators may be coordinated to implement contention-based channel access to unlicensed radio frequency spectrum bands. The operations in block 1405 were described with respect to CoMP modules 920 and / or 922 associated with receiver modules 910 and 912 and transmitter modules 930 and 932, as described with respect to FIG. 9A and / or FIG. , Transceiver module 1155 and base station RF spectrum band module 1170 associated with antenna 1160, and / or processor 1240 and related components described with respect to FIG.

  [0122] At block 1410, a CCA state is determined that indicates whether the contention for a period of time has been won. The operations in block 1410 have been described with respect to CoMP modules 920 and / or 922, FIG. 9B associated with receiver modules 910 and 912 and transmitter modules 930 and 932, as described with respect to FIGS. 9A and / or 9B. Implemented using CCA state determination module 965, base station RF spectrum band module 1170 associated with transceiver module 1155 and antenna 1160 described with respect to FIG. 11, and / or processor 1240 and associated components described with respect to FIG. obtain.

  [0123] At block 1415, the base station may communicate the CCA state that won the contention to one or more other base stations in the CoMP cooperating set. The operations in block 1415 may optionally include CoMP modules 920 and / or 922 associated with transmitter modules 930 and 932 described with respect to FIGS. 9A and / or 9B, CCA state communication module 975 described with respect to FIG. 9B, FIG. May be implemented using the transceiver module 1155 and the base station RF spectrum band module 1170 associated with the antenna 1160 and / or the processor 1240 and related components described with respect to FIG.

  [0124] At block 1420, the base station may select one or more CCA states from one or more other base stations indicating whether one or more other base stations have won contention for the time period. Can receive. The operations in block 1420 may optionally include CoMP modules 920 and / or 922 associated with transmitter modules 930 and 932 described with respect to FIGS. 9A and / or 9B, CCA state communication module 975 described with respect to FIG. 9B, FIG. May be implemented using the transceiver module 1155 and the base station RF spectrum band module 1170 associated with the antenna 1160 and / or the processor 1240 and related components described with respect to FIG.

  [0125] In optional block 1425, the base station may perform CoMP communication with the UE using one or more other base stations in a CoMP cooperating set having a CCA state that is winning contention for the time period. You can start. The operations in block 1425 may be performed in some cases with CoMP modules 920 and / or 922 associated with receiver modules 910 and 912 and transmitter modules 930 and 932 described with respect to FIGS. 9A and / or 9B, and with CoMP described with reference to FIG. 9B. Coordination module 980, base station RF spectrum band module 1170 associated with transceiver module 1155 and antenna 1160 described with respect to FIG. 11, and / or processor 1240 and related components described with respect to FIG.

  [0126] In this manner, method 1400 may provide wireless communication where CoMP communication may be provided in a contention based channel access procedure. Note that the method 1400 is only one implementation and the operation of the method 1400 may be reordered or otherwise modified to allow other implementations.

  [0127] FIG. 15 is a flowchart conceptually illustrating an example of a method of wireless communication according to an aspect of the disclosure. For clarity, the method 1500 is described with respect to the base station, eNB, or device described with respect to FIG. 1, FIG. 2, FIG. 3, FIG. Reference is made below to each of 105, 205, 305, 405, 605, 705, 905, 955, 1105 and / or 1205. In one example, the base station may execute one or more sets of codes for controlling the functional elements of the base station to perform the functions described below.

  [0128] At block 1505, a CCA procedure is performed at the base station to contend for access to the unlicensed radio frequency spectrum band. In some examples, performing the CCA procedure may include performing an eCCA procedure. In some examples, multiple base stations of the same and / or different operators may be coordinated to perform contention-based channel access to the radio frequency spectrum band. The operations at block 1505 were described with respect to CoMP modules 920 and / or 922 associated with receiver modules 910 and 912 and transmitter modules 930 and 932 as described with respect to FIGS. 9A and / or 9B, FIG. , Transceiver module 1155 and base station RF spectrum band module 1170 associated with antenna 1160, and / or processor 1240 and related components described with respect to FIG.

  [0129] At block 1510, a CCA state may be determined that indicates whether the contention for a period of time has been won. The operations in block 1510 are optionally described with respect to CoMP modules 920 and / or 922 associated with receiver modules 910 and 912 and transmitter modules 930 and 932 described with respect to FIGS. 9A and / or 9B, FIG. 9B. Implemented using the CCA state determination module 965, the base station RF spectrum band module 1170 associated with the transceiver module 1155 and antenna 1160 described with respect to FIG. 11, and / or the processor 1240 and related components described with respect to FIG. obtain.

  [0130] At block 1515, the base station may communicate the CCA state to one or more other base stations in the CoMP cooperating set. The operations in block 1515 may optionally include CoMP modules 920 and / or 922 associated with transmitter modules 930 and 932 described with respect to FIGS. 9A and / or 9B, CCA state communication module 975 described with respect to FIG. 9B, FIG. May be implemented using the transceiver module 1155 and the base station RF spectrum band module 1170 associated with the antenna 1160 and / or the processor 1240 and related components described with respect to FIG.

  [0131] At block 1520, the base station may forward a channel state information (CSI) report from the base station to one or more other base stations in the CoMP cooperating set. The operations in block 1520 may optionally include CoMP modules 920 and / or 922 associated with transmitter modules 930 and 932 described with respect to FIGS. 9A and / or 9B, CCA state communication module 975 described with respect to FIG. May be implemented using the transceiver module 1155 and the base station RF spectrum band module 1170 associated with the antenna 1160 and / or the processor 1240 and related components described with respect to FIG.

  [0132] In this manner, method 1500 may provide wireless communication where CoMP communication may be provided in a contention based channel access procedure. Note that the method 1500 is only one implementation and the operation of the method 1500 may be reordered or possibly modified as other implementations are possible.

  [0133] FIG. 16 is a flowchart conceptually illustrating an example of a method of wireless communication, according to an aspect of the disclosure. For clarity, the method 1600 is described with respect to the UEs 115, 215, 315, 415, 615 described above with respect to FIGS. 1, 2, 3, 4, 6, 7, 10, and / or FIG. The following is described with reference to each of 715, 1015 and / or 1215. In one example, the UE may execute one or more sets of codes for controlling functional elements of the UE to perform the functions described below.

  [0134] At block 1605, the UE wins contention for a time period with one or more base stations in the CoMP cooperating set based at least in part on a CCA procedure for access to the unlicensed radio frequency spectrum. Determine whether or not. The operations in block 1605 may optionally include UE RF spectrum band module 1040 and / or UE CoMP module 1055 associated with transceiver module 1070 and antenna 1180 described with respect to FIG. 10, and / or processor 1280 and relationships described with respect to FIG. Can be implemented using the following components:

  [0135] At block 1610, the UE may receive CoMP communications from one or more base stations in the CoMP cooperating set that won the contention. Operation in block 1610 may optionally include UE RF spectrum band module 1040 and / or UE CoMP module 1055 associated with transceiver module 1070 and antenna 1080 described with respect to FIG. 10, and / or processor 1280 and relationships described with respect to FIG. Can be implemented using the following components:

  [0136] In this manner, method 1600 may provide wireless communication in which a UE may operate using CoMP communication in a contention based channel access deployment. Note that the method 1800 is only one implementation and the operation of the method 1800 may be reordered or possibly modified to allow other implementations.

  [0137] The detailed description set forth above with respect to the accompanying drawings describes exemplary examples and is not intended to represent the only examples that may be implemented or fall within the scope of the claims. As used throughout this specification, the term “exemplary” means “acting as an example, instance, or illustration” and means “preferred” or “advantageous over other examples” do not do. The detailed description includes specific details for the purpose of providing an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

  [0138] Information and signals may be represented using any of a wide variety of techniques and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any of them Can be represented by a combination.

  [0139] Various exemplary blocks and modules described in connection with the disclosure herein include general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other It may be implemented or implemented using programmable logic devices, individual gate or transistor logic, individual hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, eg, a DSP and microprocessor combination, a plurality of microprocessors, one or more microprocessors associated with a DSP core, or any other such configuration. .

  [0140] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the present disclosure and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features that implement a function can also be physically located at various locations, including being distributed such that portions of the function are implemented at different physical locations. Also, as used herein, including the claims, “or” used in a list of items beginning with “at least one of” is, for example, “A, B, or An enumeration of “at least one of C” indicates a disjunctive enumeration as meaning A or B or C or AB or AC or BC or ABC (ie, A and B and C).

  [0141] Computer-readable media includes both computer storage media and computer communication media including any medium that enables transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, computer-readable storage media is in the form of RAM, ROM, EEPROM, CD-ROM, or other optical disk storage, magnetic disk storage or other magnetic storage device, or instructions or data structures. Any other medium that can be used to carry or store the desired program code means and that can be accessed by a general purpose or special purpose computer, or a general purpose or special purpose processor. Any connection is also properly termed a computer-readable medium. For example, software from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (“DSL”), or wireless technologies such as infrared, wireless, and microwave When transmitted, coaxial technology, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the media definition. As used herein, a disk and a disc are a compact disc (CD), a laser disc (registered trademark) (disc), an optical disc (disc), a digital versatile disc (DVD). ), A floppy disk, and a Blu-ray disk, where the disk normally reproduces data magnetically and is a disc. Replays data optically with a laser. Combinations of the above are also included within the scope of computer-readable media.

  [0142] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Throughout this disclosure, the term “example” or “exemplary” indicates an example or instance, and does not imply or require any preference for the mentioned example. Thus, the present disclosure should not be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0142] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Throughout this disclosure, the term “example” or “exemplary” indicates an example or instance, and does not imply or require any preference for the mentioned example. Thus, the present disclosure should not be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.
The invention described in the scope of claims at the beginning of the application will be appended.
[1]
[C1]
A method for wireless communication by a base station in a coordinated multipoint (CoMP) coordinated set of base stations in a wireless communication network, comprising:
Performing a Clear Channel Assessment (CCA) procedure to compete for access to unlicensed radio frequency spectrum bands;
Determining a CCA state that indicates whether the contention for the time period has been won;
Communicating the CCA state to one or more other base stations in the CoMP cooperating set;
A method comprising:
[C2]
Performing the CCA procedure,
The method of C1, comprising performing an enhanced clear channel assessment (eCCA) procedure.
[C3]
Further comprising initiating CoMP communication with a user equipment (UE) using one or more base stations in the CoMP cooperating set having a CCA state winning the contention for the time period. The method according to C1.
[C4]
Further comprising receiving one or more CCA states of the one or more other base stations indicating whether the one or more other base stations have won contention for the time period. The method according to C1.
[C5]
The time period corresponds to a time period for transmitting a radio frame comprising a plurality of subframes;
The method of C4, wherein the communication and the reception are performed during a CCA state notification time period of the radio frame.
[C6]
The method of C5, wherein initiating CoMP communication is performed after the CCA state notification time period of the radio frame.
[C7]
The method of C5, wherein the CCA status notification time period can be determined based at least in part on a nature of the CCA procedure.
[C8]
Initiating the CoMP communication includes transmitting a control channel to the UE by a base station of the one or more base stations, and remaining base stations of the one or more base stations. Transmitting the one or more data channels to the UE by the method of C3 above.
[C9]
Starting the CoMP communication,
Initiating dynamic point selection (DPS) communication from the base station to the user equipment (UE) during at least a portion of the time period;
Suspending DPS communication from the base station while one of the one or more other base stations is performing DPS communication with the UE;
The method according to C3, comprising:
[C10]
At least a part of the time period corresponds to a CCA state notification time period of a radio frame, and the DPS communication from the base station is stopped.
Suspending wireless transmission to the UE, and / or
The method of C9, comprising transmitting to one or more other UEs to maintain a transmission bandwidth threshold.
[C11]
The portion of the time period corresponds to a time period of a first radio frame, and stopping DPS communication from the base station stops transmitting to the UE during a second radio frame. The method according to C9, comprising:
[C12]
The method of C1, further comprising forwarding a channel state information (CSI) report from the base station to the one or more other base stations in the CoMP cooperating set.
[C13]
The method of C12, wherein the CSI report includes a rank indicator (RI) for use by the one or more other base stations in the CoMP cooperating set.
[C14]
The RI is the one or more in the CoMP cooperating set when a subsequent CCA procedure of the base station fails and the one or more other base stations win the contention of the subsequent CCA procedure. The method of C13, wherein the method is for use by a plurality of other base stations.
[C15]
For use by the one or more other base stations when the subsequent CCA procedure of the base station fails and the one or more other base stations win the contention of the subsequent CCA procedure The method of C1, further comprising: transferring a reference rank indicator of from the base station to the one or more other base stations in the CoMP cooperating set.
[C16]
An apparatus for wireless communication by a base station in a coordinated multipoint (CoMP) cooperating set of base stations in a wireless communication network comprising:
Means for performing a clear channel assessment (CCA) procedure to compete for access to unlicensed radio frequency spectrum bands;
Means for determining a CCA status that indicates whether or not the contention for the time period has been won;
Means for communicating the CCA state to one or more other base stations in the CoMP cooperating set;
A device comprising:
[C17]
Means for initiating CoMP communication with a user equipment (UE) using one or more base stations in the CoMP cooperating set having a CCA state winning the contention for the time period The apparatus according to C16.
[C18]
Means for receiving one or more CCA states of the one or more other base stations indicating whether the one or more other base stations have won contention for the time period; The apparatus according to C16.
[C19]
The time period corresponds to a time period for transmitting a radio frame comprising a plurality of subframes;
The apparatus of C18, wherein the communication and the reception are performed during a CCA state notification time period of the radio frame.
[C20]
The apparatus according to C19, wherein starting CoMP communication is performed after the CCA state notification time period of the radio frame.
[C21]
Initiating CoMP communication includes transmitting a control channel to the UE by a base station of the one or more base stations, and by remaining base stations of the one or more base stations. Transmitting the one or more data channels to the UE. The apparatus of C17, comprising:
[C22]
Initiating CoMP communication
Initiating dynamic point selection (DPS) communication from the base station to the user equipment (UE) during at least a portion of the time period;
Suspending DPS communication from the base station while one of the one or more other base stations is performing DPS communication with the UE;
The apparatus according to C17, comprising:
[C23]
At least a part of the time period corresponds to a CCA state notification time period of a radio frame, and the DPS communication from the base station is stopped.
Suspending wireless transmission to the UE, and / or
The apparatus of C22, comprising transmitting to one or more other UEs to maintain a transmission bandwidth threshold.
[C24]
The portion of the time period corresponds to a time period of a first radio frame, and stopping DPS communication from the base station stops transmitting to the UE during a second radio frame. The apparatus according to C22, comprising:
[C25]
The apparatus of C16, further comprising forwarding a channel state information (CSI) report from the base station to the one or more other base stations in the CoMP cooperating set.
[C26]
The apparatus of C25, wherein the CSI report includes a rank indicator (RI) for use by the one or more other base stations in the CoMP cooperating set.
[C27]
The RI is the one or more in the CoMP cooperating set when a subsequent CCA procedure of the base station fails and the one or more other base stations win the contention of the subsequent CCA procedure. The apparatus of C26 above, for use by a plurality of other base stations.
[C28]
An apparatus for wireless communication by a base station in a coordinated multipoint (CoMP) cooperating set of base stations in a wireless communication network comprising:
A processor;
A memory in electronic communication with the processor;
An instruction stored in the memory, the instruction comprising:
Performing a Clear Channel Assessment (CCA) procedure to compete for access to unlicensed radio frequency spectrum bands;
Determining a CCA state that indicates whether the contention for the time period has been won;
Communicating the CCA state to one or more other base stations in the CoMP cooperating set;
A device that is executable by the processor to cause the device to execute.
[C29]
A method for wireless communication by user equipment in a wireless communication network comprising:
Based at least in part on a Clear Channel Assessment (CCA) procedure for access to unlicensed radio frequency spectrum bands, one or more base stations in a Coordinated Multipoint (CoMP) cooperating set win the contention for the time period. Determining whether or not
Receiving a CoMP communication from the one or more base stations in the CoMP cooperating set that has won the conflict;
A method comprising:
[C30]
The method of C29, further comprising transmitting a reference signal measurement to the one or more base stations based on the determination.

Claims (30)

A method for wireless communication by a base station in a coordinated multipoint (CoMP) coordinated set of base stations in a wireless communication network, comprising:
Performing a Clear Channel Assessment (CCA) procedure to compete for access to unlicensed radio frequency spectrum bands;
Determining a CCA state that indicates whether the contention for the time period has been won;
Communicating the CCA state to one or more other base stations in the CoMP cooperating set;
A method comprising: Performing the CCA procedure,
The method of claim 1, comprising performing an enhanced clear channel assessment (eCCA) procedure.   Further comprising initiating CoMP communication with a user equipment (UE) using one or more base stations in the CoMP cooperating set having a CCA state winning the contention for the time period. Item 2. The method according to Item 1.   Further comprising receiving one or more CCA states of the one or more other base stations indicating whether the one or more other base stations have won contention for the time period. Item 2. The method according to Item 1. The time period corresponds to a time period for transmitting a radio frame comprising a plurality of subframes;
The method according to claim 4, wherein the communication and the reception are performed during a CCA state notification time period of the radio frame.   6. The method of claim 5, wherein initiating CoMP communication is performed after the CCA state notification time period of the radio frame.   6. The method of claim 5, wherein the CCA status notification time period may be determined based at least in part on the nature of the CCA procedure.   Initiating the CoMP communication includes transmitting a control channel to the UE by a base station of the one or more base stations, and remaining base stations of the one or more base stations. Transmitting one or more data channels to the UE. Starting the CoMP communication,
Initiating dynamic point selection (DPS) communication from the base station to the user equipment (UE) during at least a portion of the time period;
Suspending DPS communication from the base station while one of the one or more other base stations is performing DPS communication with the UE;
The method of claim 3 comprising: At least a part of the time period corresponds to a CCA state notification time period of a radio frame, and the DPS communication from the base station is stopped.
10. The method of claim 9, comprising discontinuing wireless transmission to the UE and / or transmitting to one or more other UEs to maintain a transmission bandwidth threshold.   The portion of the time period corresponds to a time period of a first radio frame, and stopping DPS communication from the base station stops transmitting to the UE during a second radio frame. The method of claim 9, comprising:   The method of claim 1, further comprising forwarding a channel state information (CSI) report from the base station to the one or more other base stations in the CoMP cooperating set.   13. The method of claim 12, wherein the CSI report includes a rank indicator (RI) for use by the one or more other base stations in the CoMP cooperating set.   The RI is the one or more in the CoMP cooperating set when a subsequent CCA procedure of the base station fails and the one or more other base stations win the contention of the subsequent CCA procedure. 14. A method according to claim 13, for use by a plurality of other base stations.   For use by the one or more other base stations when the subsequent CCA procedure of the base station fails and the one or more other base stations win the contention of the subsequent CCA procedure The method of claim 1, further comprising: transferring a reference rank indicator from the base station to the one or more other base stations in the CoMP cooperating set. An apparatus for wireless communication by a base station in a coordinated multipoint (CoMP) cooperating set of base stations in a wireless communication network comprising:
Means for performing a clear channel assessment (CCA) procedure to compete for access to unlicensed radio frequency spectrum bands;
Means for determining a CCA status that indicates whether or not the contention for the time period has been won;
Means for communicating the CCA state to one or more other base stations in the CoMP cooperating set;
A device comprising:   Means for initiating CoMP communication with a user equipment (UE) using one or more base stations in the CoMP cooperating set having a CCA state winning the contention for the time period The apparatus of claim 16.   Means for receiving one or more CCA states of the one or more other base stations indicating whether the one or more other base stations have won contention for the time period; The apparatus of claim 16. The time period corresponds to a time period for transmitting a radio frame comprising a plurality of subframes;
The apparatus according to claim 18, wherein the communication and the reception are performed during a CCA state notification time period of the radio frame.   The apparatus according to claim 19, wherein initiating CoMP communication is performed after the CCA state notification time period of the radio frame.   Initiating CoMP communication includes transmitting a control channel to the UE by a base station of the one or more base stations, and by remaining base stations of the one or more base stations. 18. The apparatus of claim 17, comprising transmitting one or more data channels to the UE. Initiating CoMP communication
Initiating dynamic point selection (DPS) communication from the base station to the user equipment (UE) during at least a portion of the time period;
Suspending DPS communication from the base station while one of the one or more other base stations is performing DPS communication with the UE;
The apparatus of claim 17, comprising: At least a part of the time period corresponds to a CCA state notification time period of a radio frame, and the DPS communication from the base station is stopped.
23. The apparatus of claim 22, comprising discontinuing wireless transmission to the UE and / or transmitting to one or more other UEs to maintain a transmission bandwidth threshold.   The portion of the time period corresponds to a time period of a first radio frame, and stopping DPS communication from the base station stops transmitting to the UE during a second radio frame. 23. The apparatus of claim 22, comprising:   17. The apparatus of claim 16, further comprising forwarding a channel state information (CSI) report from the base station to the one or more other base stations in the CoMP cooperating set.   26. The apparatus of claim 25, wherein the CSI report includes a rank indicator (RI) for use by the one or more other base stations in the CoMP cooperating set.   The RI is the one or more in the CoMP cooperating set when a subsequent CCA procedure of the base station fails and the one or more other base stations win the contention of the subsequent CCA procedure. 27. The apparatus of claim 26, for use by a plurality of other base stations. An apparatus for wireless communication by a base station in a coordinated multipoint (CoMP) cooperating set of base stations in a wireless communication network comprising:
A processor;
A memory in electronic communication with the processor;
An instruction stored in the memory, the instruction comprising:
Performing a Clear Channel Assessment (CCA) procedure to compete for access to unlicensed radio frequency spectrum bands;
Determining a CCA state that indicates whether the contention for the time period has been won;
An apparatus capable of being executed by the processor to cause the apparatus to perform communicating the CCA state to one or more other base stations in the CoMP cooperating set. A method for wireless communication by user equipment in a wireless communication network comprising:
Based at least in part on a Clear Channel Assessment (CCA) procedure for access to unlicensed radio frequency spectrum bands, one or more base stations in a Coordinated Multipoint (CoMP) cooperating set win the contention for the time period. Determining whether or not
Receiving CoMP communications from the one or more base stations in the CoMP cooperating set that have won contention.   30. The method of claim 29, further comprising transmitting a reference signal measurement to the one or more base stations based on the determination.

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